Early childhood dental caries, the disease process primarily responsible for tooth decay among young children, is an extremely common condition worldwide. Beyond its role as a source of pain and infection, dental caries may impact a child's ability to eat, sleep, and concentrate in school. Nutrition, along with infant and toddler feeding practices such excessive snacking and bottle use, plays an import role in the development of dental caries, and thus, efforts to improve nutrition and feeding behavior may yield oral health benefits above and beyond improvements in general health. In a country such as Brazil, which simultaneously faces public health challenges from both persistent under nutrition and an increasingly overweight population, maternal nutrition counseling to improve feeding practices from the very start of life may prove particularly impactful. With this in mind, the Brazilian Ministry of Health developed a set of targeted recommendations: the Ten Steps of Healthy Feeding for Brazilian Children Under Two Years of Age. While prior evidence suggests that the Ten Steps recommendations can effectively improve oral and overall health outcomes when incorporated into an intensive home intervention program, home visits do not represent an affordable public health option on a large scale. It is not known whether as an alternative, using the existing public health infrastructure for delivery of these nutrition education messages, is similarly well suited for effective caries prevention. Aiming to answer this question, twenty public primary healthcare service sites in the city of Porto Alegre, Brazil were enrolled in a randomized controlled field trial beginning in 2008. At about half the sites, health service providers were trained to provide the nutrition education outlined in the Ten Steps program to mothers during routine prenatal and pediatric visits. For those service providers working at sites in the control group, there was no interference with usual practices. This project will evaluate the effectiveness of this program of healthcare provider training in the Ten Steps recommendations to improve oral health outcomes in preschool age children. It is expected that compared to children whose mothers attended healthcare service sites in the control group, those visiting sites delivering maternal nutrition education will be less likely to have experienced tooth decay or severe tooth decay, will be less likely to fall outside the normal growth standards for height and weight, and will demonstrate an improved diet consisting of fewer high-sugar and high-fat foods, among other health benefits. Should this program prove effective, it could serve as a model for future public health policy in a variety of settings. Even should substantial differences not be observed across the two groups, this study will help to identify the individual feeding behaviors most strongly associated with oral health and other health outcomes. Such information is directly applicable to the development of affordable, targeted strategies for better prevention of early childhood dental caries in a variety of settings.